Apparatus for treating paper stocks



June 29, 1965 H. lamwELl.

APPARATUS FOR TREATING PAPER STOCKS 2 Sheets-Sheet '1 Filed NOV. 1. 1962 wgmva..

VIIIIIIIIII lll/1111111 INVENTOK HowARo amm-:LL

ATTORNEY June 29, 1965 H. BIDWELL APPARATUS FOR TREATING PAPER STOCKS 2 Sheets-Sheet 2 Filed Nov. 1. 1962 INV'ENToR. HOWARD BmwELL ATTORNEY.

United States Patent O 3,191,876 APPARATUS FOR TREATING PAPER STOCKS Howard Bidwell, 56 Aldrich St., Granby, Mass., assignor of fifty percent to Rachel Bidwell, Granby, Mass. Filed Nov. 1, 1962, Ser. No. 234,645 4 Claims. (Cl. 241--296) This application is a continuation-impart of application Serial No. 89,423, filed February l5, 1961, now abandoned.

The present invention relates generally to new and useful improvements in apparatus `for processing paper stock by iiowing waterborne stock over land against and between spaced granular-surfaced elements for purposes of separating the fibers from the paper stock aggregate and iibrillating the separated fibers by means of the combing action of a granular surface or surfaces.

It will be helpful to an understanding of my invention first to briey consider some of the essential points and more important features and aspects thereof, so that same may be kept in mind during subsequent reading of the detailed description of the practical embodiment of my improvements -and illustrations thereof in the hereunto annexed drawings.

This invention is directed more particularly to improvements in means for reinforcing the vitriied porous granular structure of a rotor body, securable to a supporting and driving member inclusive of a complement of reinforcing devices, each extending outwardly from said supporting and driving member for embedding in a cooperant curable or settable resinous mass contained in an appropriately-aligned recess within an interiorly resin-saturated rotor body, all to allow a structure which will effectuate a transmittal of the driving force from the supporting and driving member to the rotor body interior.

Among the various types of bonding of the silica carbide and alumina oxide granules, I have found that the vitriiied type of bonding is the best suited for use in the processing of fibrous materials for paper stocks as herein comprehended, but such type is subject to certain limitations and weaknesses to thermal and other shock and has low tensile and limited compressive strength properties, due to the very nature of the glass content of the vitrifying bonding medium itself.

These weaknesses are further aggravated by the very porous nature of the granular structure, due to the large percentage of volume constituting the voids within the structure, as necessitated when a predominantly certainsize granule is a desideratum in order to attain certain granular surface effects and characteristics for performing a predetermined fiber treatment function of the process of fiber development characteristics, as measured by such tests as Mullen, tensile, tare and liber length in effectuating attainment of a desired accepted stock condition.

Due to the limited amount of so-called filler of lower sized granules and bonding media which can be used in the compact mixture formulae for a given desired granular surface effect, the porosity of the structures are necessarily high, causing the granular structure to be of low tensile and compressive strength and to have a low resistance to thermal and work load shocks and to be generally of a fragile nature.

While the vitrilied type of bonding is the only satisfactory method of bonding non-metallic granules, such as silica carbide and alumina oxide, as used in the processing of paper stocks, I have determined that the characteristic nature of such vitrified bonded structures is radicallyA changed from the objectionable brittle and fragile nature when the voids of the porous structure are impregnated with an epoxy resin having a demonstrated capacity for 3,191,876 Patented June 29, 1,965

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causing the porous structure to be reenforced so as to resist fracture under shock and abuse and overloading within the limits of the processing requirements.

The manifestation of these new and improved properties of the granular structures so reenforced is attributed to the fact that a vastly greater surface area of the constituent granules is exposed to the voids interiorly of the structure than is in actual contact with adjacent granules through the vitritied bonding medium as revealed by microscopic examination.

When the heretofore unutilized granular area within the voids interiorly of the normally porous structure is utilized for bonding purposes with a suitable shock resistant tenacious high strength epoxy resin, the brittle and fragile nature of the vitriied structure is altered and changed to a higher tensile and -compressive strength which resists fracture under severe load and shock conditions due to a greater area of the constituent granules being bonded bythe epoxy resin than by the vitriiication.

The invention further comprehends and exploits the phenomenon, characteristic of epoxy resin 'bonded untreated granular-bodied structures, as exemplified in my earlier-issued patents and in my copending applications, itemized below, that granular bodies as prepared, shaped, tooled and finished, will resist fracture under extreme pressure, shock and abuse within those bonded regions Iand adjacent thereto, wherefore it is among other purposes of this invention to advantageously utilize the phenomenon sufficiently throughout the entirety of the granular structure by virtue of a filling of the porous granular structure voids interiorly of the body with suitable high-strength shock-resistant epoxy bonding agents so as to increase many fold the constituent granule bonded area.

Stated in another way, the invention envisions a built-up porous granular bonded structure for processing iibrous materials and a method of constructing same to overcome certain diiculties heretofore encountered in interrelating a rigid, inflexible, bonded abrasive element and a rigid element which is to reinforce or support same and comprehends a multiplicity of spaced recesses extending into the interior of the porous granular body from a supporting side thereof, the recesses serving to allow a complete impregnation of the inherent voids interiorly of the porous granular body between the recesses thereof by the application thereinto of an epoxy resin whereby is provided a continuous impregnation throughout the 360 of the annulus, into which epoxy resin reinforced area a plurality of rigid reenforcing projections formed as integral parts of the rigid element are embedded by a cementious bonding means.

Apparatus of the type to which this invention pertains includes a rotor body, which comprises hard irregular granules bonded together by a vitriiied bond to form a porous granular surfaced body wherein the working faces thereof have been contouredto direct and manipulate the stock, and which rotor body is secured to a relatively rigid or iniiexible companion element serving as a support and/ or reinforcement thereof, the combined structure being driven at high speeds and under heavy loads and allowing a porous type of surface in which the outermost granules may project outwardly into the flow stream and a solid interior by virtue of having incorporated thereinto a filler having bonding or other beneficial characteristics capable of acting in conjunction with and supplementing the primary bond with which the body is initially formed to increase the life of such treated portions and to improve the heat conduction ability thereof, as made necessary by the effectiveness of the high frictional surfaces where such heat is of course generated.

By such means, I allow a system of increasing the heat dissipating properties of the granular structure of the processing part of the rotating assemblies by filling the voids of the granular structure part, as to cause the structure to be more dense and free of voids and therefore a more eftiicient heat conductor in disipating internal heat that may otherwise accumulate to a destructive temperature point.

Such types of rotor bodies are exemplified in my Patents Nos. 2,912,174 and 2,936,128, dated November 10, 1959 and May 10, 1960 respectively, and also in my copending applications, Serial Number 26,527, filed May 3, 1960; now Patent No. 3,058,678 and Serial No. 78,072, filed December 23, 1960, now abandoned.

Cognate subject matter not claimed is embraced in my companion copending application above noted, said copending application relatingto means for reenforcing and supporting rotor bodies, of the above delineated character, it being notorious that such rotor bodies are subject, in operation, to thermal shock as well as to internal stresses resulting from the centrifugal forces imposed by high speeds and heavy loading and impact, which shock and stresses tend to cause fractures of the rotor bodies. These working stresses are intensified and set up in complicated and varying patterns in the body of the rotors, particularly in the cases of deeply contoured rotors.

Herein, I teach a novel means whereby these difficulties and objections are better overcome and wherein the working and driving stresses are more uniformly distributed through the rotor body and absorbed or transmitted to the driving support, thereby to minimize, if not to eliminate, the recognized objectionable features of prior art constructions.

It may be stated, accordingly, that it is a principal object hereof to furnish an improvement in the art which, on the basis of the factors involved, is capable of solving the difficulties heretofore encountered and assures ways and means for forming a unitary rotor body wherein the working and driving stresses are more uniformly distributed through the rotor body for absorption or transmitted to the driving support, whether said rotor body is of a one-piece construction or constitutes a plurality of superposed members.

As a further refinement, I reliably insure that, if breakage or fracture of the rotor body should occur, the fractured positions are held in place, thereby preventing disintegration of the rotor with resulting damage to other equipment parts.

Specifically, in the instant disclosure, I teach means for reenforcing a vitrified porous granular structure rotor body which is secured to a reenforcing driving support, as disclosed in FIG. 9 of said copending application, Serial Number 89,423, now abandoned, by mpregnating the porous granular body, shown in FIG. 7 thereof, with a thin, low viscous, low centipoise, mpregnating type of high strength epoxy resin having a demonstrated capacity to filter, while in the tiuid state, through the porous structure prior to taking a permanent set.

Another of the dominant aims hereof is to provide a mechanical junction or union between cooperant parts that will overcome the difficulties and deficiencies referred to and to provide a practical and economical method of achieving the same.

And another purpose hereof is to provide a porous granular structure which, when reenforced as envisioned, will allow a maximum of resistance to thermal shock and increased workloads in operational use and which permit of long continued use with a minimum of need for repair or maintenance on the part of the user, all resulting in important distinct advantages in economy of manufacture, ease of operation, reliablity of performance, and capability of ready assembly to provide positiveness and ease of action under the varying conditions of practical use.

closure below. To the end of attaining these objects and advantages and others hereinafter reasonably appearing, it will be explained that the invention consists substantially in the combination, construction, configuration, location and function of parts, as herein described in detail, although it will be apparent that the physical embodiment delineated, albeit the preferred exemplfication, is only indicative of but one of the multiplicity of ways in and purposes for which the principles of the invention may be employed. Same is submitted as a best known embodiment of the invention with a View to illustrating and explaining the precise nature of its principles and their embodiment for practical use, in order that others skilled in the art to which the invention pertains may be enabled to adapt and modify them in numerous variations and modifications, each as may be best adapted to the conditions of any particular use.

These foregoing objects and other incidental ends and The precise construction of the figures of the drawings need not be slavishly followed as, of course, the construction may have to be adapted or alternatively constructed or modified in accordance with any specific use contemplated therefore. Such adaptations and/ or alternative constructions and/or modifications are intended to be comprehended within the meaning and purview and range of equivalence of the below subjoined claims, there being no intent to have this invention limited to or circumscribed by any specific details.

While all of these objects are attainable in the preferred and disclosed embodiment, it is to be understood that, by utilizing the invention only in certain of its aspects, certain of the objects may be attained individually or in sub-groups without necessarily attaining all of the objects. That is, while the advantages of the invention as here outlined are best realized when all of its features and instrumentalities are combined, useful embodiments may be produced involving less than the whole.

The characteristic features which I consider to be novel with my invention, as to its construction and organization and as to its methods of manufacture and operation, will be better understood from a consideration of the following detailed description forming a part of this specification, when read in conjunction with the illustrations in the accompanying drawings, wherein like characters of reference are employed to designate like or corresponding parts throughout the several views and in which:

FIG. 1 is a fragmentary plan view of a proposed blank of a granular rotor body;

FIG. 2 is a vertical central sectional view through the structure shown in FIG. l;

FIG. 3 is a vertical central sectional view, similar to FIG. 2, showing the method of preparing the preliminarily-fired rotor body;

FIG. 4 is a side elevational view showing the rotor and reenforcing support combination with certain portions being shown in section;

FIG. 5 is a greatly enlarged, fragmentary sectional view showing a groupment of the porous granules of a rotor body preliminary to the treatment envisioned by the invention;

FIG. 6 is a view, similar to FIG. 5, following the treatment envisioned by the invention; and

FIG. 7 is an exploded view showing both the reenforcing and supporting element and the rotor body in vertical central sectional view.

In the following description and appended claims, vari- I ous components and details thereof will be identified by specific names and expressions for purposes of convenience and of identifying various components, they being used in a generic and descriptive sense only. They are not intended to exclude any reasonable equivalents of the features shown and described or portions thereof.

With continued reference now to the drawings, which illustrate a typical and preferred embodiment of the invention for the purpose of disclosureV and form a part of this specification, I have shown, in FIGS. 1 and 2,

a prepared, fired form of an annular or circularly-cylindrical porous granular rotor body, which annulus is generally indicated by 25, prepared in accordance with the general procedure disclosed in said copending application, Serial Number 78,072.

In its formation, said body is preferentially, though not obligatorily, provided on its working surfaces with a multiplicity of relatively shallow grooves 26 and with a plurality of elongated, generally-cylindrical, uniformlyspaced reenforcing recesses 27, extending inwardly from one of the planar surfaces thereof and preferentially equispaced as to each other with centers located on one or the other of a pair of circles concentric with the rotor body with the axes of the recesses extending parallel to the axis of the rotor body.

Itis here to be stated that whereas, in the illustrated embodiment, a pair of such circles are taught, it is conceivable that only one such circle may be desired in certain instances.

Additionally, the rotor body will be provided with a central bore 28 concentric with the said circles or circle, which bore will be enlarged, as at 29, adjacent one planar surface of the formed rotor body, to provide an annular shoulder 30, for purposes to become apparent subsequently.

Said rotor body 25 will also be formed with a land 31 allowing an annular shoulder 32, as shown.

With the rotor body so formed, it is initially chilled, preliminary to the processing of the surfaces thereof, with a low temperature melting point wax or paraffin. The chilling will serve to preclude the attainment of more than a surface coating, or at very most, to allow no more than a minimal penetration of the wax or paraffin coating into the body. v

An enclosing structure, comprised of a circular band or hoop A, of metal, placed upon a at supporting plate B, defines a treating area within which the wax-treated rotor body may be disposed with another fiat covering plate C being disposed over the rotor body following insertion thereinto, said members A, B and C having interior linings of sponge rubber D covering the inwardly-facing surfaces to allow a rubber lining between each said member and the adjacent confronting rotor body surface.

It is here to be 'explained that said lining, reenforced by the said metal members of the enclosing structure, cooperate to'hold the wax coating firm when subjected to pressure.

And now with reference to FIG. 5, I have illustrated therein a groupment of granules 50 with adjacent intercommunicating voids or interstices or spaces 51 and with the outer surface of the groupment being so coated with a film of wax or paran delineated by numeral 52.

Following such preliminary wax coating, the chilled treated body is allowed to set and to restore itself to normal room temperature.

In carrying out the invention, I then charge the reenforcing recesses 27 with a thin, fluent, free-owing, high-strength, impregnating, epoxy resin of suitable low viscosity such as from a pouring container E, which resin has a capacity for penetrating the circumadjacent zone of the porous granular material of the rotor body in manner to fill the voids or interstices or spaces 51 between the fragments and to ow toward the wax coated exterior surfaces, such filled resin within the voids 51 being represented by 53 in FIG. 6.

As the resin settles relative to and within the reenforcing recesses, additional charges of resin may be'necessitated and may be added thereinto, with the procedure being repeated until the porous structure attains a saturation point, recognized when the recesses remain filled with said resin, such within-the-recesses increments of resin constituting a plurality of conncting or bridging elements, in the form of columns or masses, as will hereinafter appear.

Said saturation point having been reached and before the liquid epoxy resin had had opportunity to settle, the treated rotor body is removed from its enclosing structure, wherefore its outer and exposed surfaces are tertiarily with an epoxy resin of a thick paste consistency as by spraying, brushing or the like.

The coating will be heavy enough so that same preferably does not fill the interstices therein.

So coated, the annulus is ready for interrelation with the supporting structure or companion part which is first to be defined.

The said companion part is a rigid and inflexible member formed of metal, such assteel or cast iron, being provided with any suitable means, which may take any one of a wide variety of forms to mount or secure same to any part of a grinding mechanism, such as shaft, collar, hub, or the like.

As shown, the said companion part comprises a rigid base or supporting plate 33, formed with a rim rib 34, and provided with a plurality of downwardly-extending reenforcing rods 35 tightly engaged at their upper ends in tapped recesses in base plate 33 and further provided with a central hold-down bushing 38 which, as shown, takes the form of a cylinder welded or otherwise secured to the base plate, and which may be further provided with a keyway for splining base plate 33 to the shouldered portion of a drive shaft 40.

As shown, and as describeid above, supporting plate 33 and reenforcing rods 35 constitute separable instrumentalities. Conceivably, said rods could be cast with Said plate.

The said rods comprise a multiplicity of uniformly distributed, strong and rigid, individual masses in the form of columns or posts of effective cross-section and may be threaded throughout their lengths as a means for enhancing their gripping capacity. Alternatively, the rods may be otherwise surfaced in any like manner found desirable or advantageous for said strength enhancing.

It will be noted that each reenforcing rod 35 is slightly smaller, diameterwise, than the respective recess 27 within which it is receivable so as to substantially centrally engage in its recess within the prespective resionus mass or column when the rotor body is assembled on the base plate, as shown in FIG.v 4.

Preliminary lto such assembly of rotor body to base plate, the base plate including uthe reenforcing rods and bushing is coated with one or vmore coats of a suitable cementious material CM for making a good adhesive bond between the metal surfaces thereof and the resin coated granular rotor body.

Such a cement of the contemplated type is the product made commercially available by Chemical Development Corporation of Danvers, Massachusetts and sold under the proprietary name Devcon.

Before the liquid epoxy resin begins to solidify, the metallic supporting plate assembly is pressed into the bonding position, as shown in FIG. 4 with the rods being allowed to settle within the respective plastic mass or column of resin within their respective recesses which, therefollowing, is allowed to harden, cure or mature in situ, the resin having in plastic form appropriate qualities such as adhesiveness to join or bond itself as a bridge between the adjacent portions of the rods and the granules adjacent the recess thereby obtaining a maximum area of junction therebetween, said resin being curable, as aforementioned, to hardened relatively rigid or inflexible condition.

The complete assembly is allowed to stand until permanently set or may be placed in a curing oven, as may be required, and depending upon the particular type of epoxy resin being employed.

The rotor body is additionally secured to base plate 33 by a cap 41 which extends over the free end of bushing 38 and annular shoulder 30 and is secured to the end of a drive shaft 40 as by a machine screw 42 or the like.

An annular granular surfaced disc 43 of the same composition as the rotor body may be cemented to cap 41 and contoured to suitably complete the upper working surface of the rotor body.

The engagement of the annular shoulder 32 of land 3.1 with the inner face of rim rib 34 directly opposes outward radial stresses in the bottom portion of the rotor body.

After curing, any existing surplus bonding resin (Le. that squeezed out in the bonding operation), may be trimmed off since the wax or paraffin coating acts as a releasing agent.

After trimming Ithe surplus bonding agent, the wax or parafiin coating is removed by lthe application of a moderate amount o f heat, leaving the processing surface clean and free of any wax or paraffin coating.

To expedite the impregnation of the porous granular form with the liquid epoxy resin, a slight air pressure may be applied to the resin filled holes 27 by suitable rubber bushed air jet nozzles.

Still greater and more rapid impregnation may be made possible with suitable jig closures of the top and bottom bore openings through which suitable vacuum connections such as F, as shown in FIG. 3, may be made for evacuating the atmosphere, which with the combined application of air pressure aforementioned, will serve to increase the effectiveness of the impregnation.

The salient point is that the reenforcing rods 35 will have been so strategically spaced and arranged in the rotor body as to distribute and absorb the stresses set up in the rotor body from the driving torque, work loads and thermal shock sustained by the rotor in operational use, as well as providing assurance against disintegration of the rotor body in the event of fracture thereof.

By filling the voids at the surface regions (working surfaces) with the wax or paraffin treatment prior to the epoxy resin application, the open granular or porous surface effect at the exterior surfaces is preserved. So treated, the subsequent filling of the interior voids will allow the forming of a solidified body, or at least a body solidified within its interior.

As known, abrasive wheels commonly known heretofore have been strengthened by the addition of a larger portion or percentage of finer grains and glazing powders, but objectionably, this system has the disadvantages of reducing the volume of voids in the structure and of diminishing the desired surface effect accordingly.

Additionally, there is the further objection in the use of an increased percentage of finer granules and glazing powders lies in the fact that the increased bonding powder so obtained is nonetheless of a vitrified character which has low thermal and other shock resistance. Contrariwise, it has been found that the epoxy resin impregnation technique hereof greatly increases both thermal and physical shock resistance and counteracts the weaknesses of vitrification.

It is to be appreciated that, as to the abrasive annulus and the support member thus rigidly secured together, and when forces are exerted, affecting any differentials in the thermal coefficients of expansion of the materials of the interrelated parts, any relative shear movement of parts is precluded by their aforedescribed unison.

Were the two members merely cemented together with a material that is hard and rigid upon setting or curing, the magnitude and directions of such shear would be such that the rigid abrasive annulus might crack, usually in radial directions.

Such destructive results are avoided, according to my invention, for, when forces arise, tending to subject the connected parts to shear, the individual bridging, laterally unsupported in the regions of the voids, can actually partake of bending and, though rigid and hard, may be strained or deformed in the manner of the deformation of a rigid structural steel truss when it is subjected to load.

As a result, the strain set up by stresses in the one part is not transmitted wholly to the other part because of the deformation or strain, in shear of the numerous hard or rigid bridging columns of resin.

When the resultant construction is put into operational use, it rises in temperature, due to the heat generated under the abrading action and expands, as temperature equilibrium throughout the entire structure is reached.

It is believed that the gist of the invention will be clearly understood from the foregoing disclosure and accordingly, further analysis thereof at this point is considered unnecessary, as I have, in accordance with the provisions of the patent statutes, described the construction and principle of operation of my invention together with the apparatus which I believe to represent the best embodiment thereof, to the end that others can, by applying current knowledge, readily adapt it for various applications without omitting features which, from the stand point of prior art, fairly constitute essential characteristics of its generic and/or specific aspects. The substitution of equivalents and other changes, modifications and alterations as circumstances may suggest or render expedient, are reasonably contemplated, the invention being susceptible of such without departing from its real spirit or underlying principles.

The claims are desired to include within the scope thereof all of said suitable variations, modifications and equivalents by which substantially the results of the invention may be obtained through the use of substantially the same or equivalent devices or means. Accordingly, limitation hereof should only be made as determined by a proper interpretation of the prior art and the scope of the subjoined claims, in which it is my intention to claim all novelty inherent herein as broadly as possible.

I claim:

1. A vitrified bonded rotor structure for use in processing waterborne stock consisting of, a porous rotor body of hard-material non-metallic granules permanently bonded together and having an exposed coarse granular stock processing outer surface, and a reenforcing epoxy resin filler incorporated into the voids of the interior bore structure of said rotor body inthe region of maximum stresses for resisting fracture.

2. A rotor member for use in the processing of Waterborne paper stock consisting of, a porous rotor body formed of permanently-bonded-together hard-material granules allowing a coarse granular stock processing outer surface area and a relatively greater surface area defining a multiplicity of interior voids impregnated with an epoxy resin, a metallic supporting and driving member connected to one face of said rotor body, a plurality of radiallyspaced reenforcing members extending from said supporting and driving member and into said rotor body for transmitting the driving force from said supporting and driving member to the interior of said rotor body.

3. The rotor member as set forth in claim 2, said rotor body being formed on its underside with a plurality of spaced recesses extending inwardly from one side thereof and having a central cylindrical opening extending therethrough, a driving support, a plurality of metal rods extending from said driving support and positioned in said into said recesses, a shaft for propelling said driving support, cementious means for bonding said resin impregnated recessed porous structure to said driving support and the projections therefrom into a unied impregnated reenforced bonded structure assembly.

References Cited by the Examiner UNITED STATES PATENTS 10 Osenburg. Bidwell 241-296 XR Baumgartner et al. 51-298 XR Skoog 51-209 Tocci-Guilbert 51-209 Hurst 51-298 Bullard 51-209 J. SPENCER OVERHOLSER, Primary Examiner. 

1. A VITRIFIED BONDED ROTOR STRUCTURE FOR USE IN PROCESSING WATERBORNE STOCK CONSISTING OF, A POROUS ROTOR BODY OF HARD-MATERIAL NON-METALLIC GRANULES PERMANENTLY BONDED TOGETHER AND HAVING AN EXPOSED COARSE GRANULAR STOCK PROCESSING OUTER SURFACE, AND A REENFORCING EPOXY RESIN FILLER INCORPORATED INTO THE VOIDS OF THE INTERIOR BORE STRUCTURE OF SAID ROTOR BODY IN THE REGION OF MAXIMUM STRESSES FOR RESISTING FRACTURE. 